An expendable underwater vehicle, such as the Expendable Mobile ASW (Anti-Submarine Warfare) Training Target (EMATT) which is available from Sippican, Inc. of Marion, Mass., is used to train naval forces in the detection, localization, tracking, and/or attack of a submarine in the ocean (i.e., to train naval forces in anti-submarine warfare). After being launched into the ocean, the expendable underwater vehicle "swims" a pre-programmed underwater course at a relatively constant speed (e.g., between 8 and 9 knots) as it acoustically simulates a submarine. The naval forces use acoustics to detect, localize, track, and/or attack the simulated submarine: After a specified time, currently about three hours, the internal batteries of the expendable underwater vehicle become exhausted, and the vehicle drops to the bottom of the ocean.
The expendable underwater vehicle can be launched into the ocean from, for example, either a surface ship or an aircraft. When launched by a surface ship, the expendable underwater vehicle is dropped into the water, usually from a short distance thereabove such that the impact is minimal and no damage results. In an aircraft launch, the expendable underwater vehicle cannot simply be dropped into the water because the impact with the water typically will damage the vehicle. Additional hardware is used in an aircraft launch to help the vehicle survive the impact with the water. The additional hardware typically is referred to collectively as an air launch assembly.
To air launch the expendable underwater vehicle, it is fitted with the air launch assembly, and then the combination typically is packaged in a sonobuoy launch container. The vehicle then can be launched from the aircraft either by using a launching tube on the aircraft that accepts the sonobuoy launch container and automatically upon command ejects the vehicle from the container, or by manually removing the vehicle from the sonobuoy launch container and dropping (launching) the unit through a launching tube or other opening in the aircraft. After the vehicle is launched from the aircraft, the air launch assembly deploys and decelerates the vehicle such that the vehicle enters the water nose-first and along its longitudinal axis.